Prostate cancer is the most common cancer in U.S. men. Existing biomarkers - digital rectal examination (DRE) and PSA - have poor sensitivity and specificity. Data from the Prostate Cancer Prevention Trial and other studies suggest that a combination of factors - constitutional (e.g., family history, genetic variations), behavioral (e.g., body mass index, diet), as well as somatic (e.g., GSTPi methylation) - can improve the discrimination between men with and without prostate cancer. The San Antonio center for Biomarkers Of Risk of prostate cancer (SABOR) is a population-based, minority and underserved-enriched, cohort study that collects extensive clinical data and biospecimens while tracking cancer-related outcomes, designed to discover, develop, and validate biomarkers of prostate cancer risk. To date, 3,142 men have been enrolled over approximately 3 years of accrual including 51% Hispanic or African American subjects. Using the entire EDRN CEVC efforts of SABOR, we have found several factors that affect prostate cancer risk including a number of genetic variations (CAG repeat length in the androgen receptor, Semaphorins 3B and 3F, SRD5A2, and variations of the Vitamin D receptor) and body mass index (higher values associated with lower levels of PSA). We have also found substantial differences in risk factors for prostate cancer in different ethnic groups (caloric intake, fat intake, micronutrient intake, body mass index, fruit and vegetable intake) as well as different performance characteristics of PSA and DRE in these ethnic/racial groups. In the SABOR renewal, we will complete recruitment of 9,000 men to the cohort, explore further these behavioral, constitutional, and somatic risk factors, develop and validate a multivariable prostate cancer risk algorithm, and conduct EDRN Network validation studies. The SABOR scientific personnel will continue to serve in their leadership positions within the Network, assisting the EDRN with the design, conduct, and analysis of early detection validation studies that will alter the standard of care of clinical practice in the United States.